Imports of package buildattr

PathSynopsis
cuelang.org/go/cue/astPackage ast declares the types used to represent syntax trees for CUE packages.
cuelang.org/go/cue/errorsPackage errors defines shared types for handling CUE errors.
cuelang.org/go/cue/parserPackage parser implements a parser for CUE source files.
cuelang.org/go/cue/tokenPackage token defines constants representing the lexical tokens of the Go programming language and basic operations on tokens (printing, predicates).